At present, the vehicle number is always on a sharp increase and to meet demand parking lots are built at the same pace, of which most are out-of-doors. When a vehicle is parked entirely under direct sunshine, the temperature inside the closed vehicle body is surely to make a verticle rise and a few hours later the vehicle seat will becomes burningly hot to be unable to sit, and it is believed such experience nearly every vehicle user has had, especially in the tropical region. When time comes for the next use of the vehicle, the vehicle user usually needs to wide open the vehicle doors, turn on the air conditioner for cooling air, and wait for several minutes until the heated air is blown away and the seat temperature reduced somehow, before he can barely enough take the seat for driving to start. Indeed, it is really time-consuming and waste of power energy.